Forums is a plugin that integrates the powerfull myBB bulletin board software with WordPress. It brings one of the most powerfull free forum softwares
The GeniusContacts plugin allows you to quickly and easily add a signup form for your GeniusContacts list.
Create a list of emails to be notified whenever a new topic is created in the specified bbPress Forum. Emails can be chosen on a per-forum basis.
Keep website users and MailChimp mailing lists in sync and create campaigns from posts.
The YouTube videos widget lets you quickly and easily display your most recent YouTube videos in your blog's sidebar.
Queue, Throttle, Send SMTP email through multiple providers. Automatic re-send when non-delivery received.
Tinypass is the best way to charge for access to content on your WordPress site.
Easily add a newsletter signup form to your site and start collecting email addresses to use with MailChimp, Constant contact or other third-party bul
Send SMS via Bongolive services in wordpress
BP FollowMe Allow members to follow other members activity.
With each new post an email is sent to every registered User in the Database. The email can be text or HTML.
This plugin adds link for the category feeds after post content.
Clifton's Lightbox implements a lightbox subscription form overlay. Features a title, list, call-to-action, and image or video.
Send SMS via wordpress
Subscription form for russian users of service E-mail Marketing (selling mailing)
Adds Feedburner Subscription Form at the end of post content.
WP FollowMe plugin allows you to add a twitter "Follow me" badge on your wordpress blog.
A Widget to add an Arrow newsletter subscription form .
This plugin generates a widget to add Google+ badge on your blog with 'Add to Circles' button.
Make it super easy for visitors to subscribe to your mailing list! Add a RuleMailer newsletter subscribe widget to your blog.
This plugin let the users to add your Google+ Page to their circle directly from your website.
This plugin lets you place a Facebook Subscribe Box on your WordPress blog as a widget.
Feedburner Counter shows the number of subscribers your feed has, even if the FeedBurner website is offline.
With this plug-in, blog owner will be able to "link" his Oempro account with WordPress and start accepting email list subscriptions.
Subscribe to Comments plugin has "subscribe without commenting" form, but you must edit your template to insert it. This plugin displays thi
Hallo Destra add social media icons in the theme wherever you want to display. Simple and looks luxurious.
A simple widgetized mailing list subscription form utilizing jQuery.
Widget show subscribe2 bar in any sidebar.
Adds MailChimp Subscribe Widget to Simple CRM
xCake Ads Lite allows you to add banners to your sidebar via a widget. Still in beta-testing mode (expect daily updates)